Preface ....................................................... XXV
List of Contributors ........................................ XXVII
1. The History of Vacuum Science and Vacuum Technology .......... 1
References .................................................. 16
Further Reading ............................................. 16
2. Applications and Scope of Vacuum Technology ................. 17
References .................................................. 24
3. Gas Laws and Kinetic Theory of Gases ........................ 25
3.1. Description of the Gas State ........................... 25
3.1.1. State Variables ................................. 25
3.1.2. Extensive Quantities ............................ 29
3.1.3. Equation of State of an Ideal Gas ............... 31
3.1.4. Mixtures of Different Gas Species ............... 33
3.2. Kinetic Theory of Gases ................................ 34
3.2.1. Model Conceptions ............................... 34
3.2.2. Wall Pressure due to Impacting Particles ........ 35
3.2.3. Maxwell-Вoltzmann Velocity Distribution ......... 37
3.2.4. Collision Rate and Effusion ..................... 40
3.2.5. Size of Gas Particles and Free Path ............. 41
3.3. Transport Properties of Gases .......................... 45
3.3.1. Pressure Dependence ............................. 45
3.3.2. Transport of Frictional Forces in Gases and
Viscosity ....................................... 47
3.3.3. Transport of Heat in Gases and Thermal
Conductivity .................................... 51
3.3.4. Diffusion ....................................... 58
3.4. Real Gases ............................................. 60
3.4.1. Equations of State .............................. 60
3.4.2. Particle Properties and Gas Behavior ............ 65
3.5. Vapors ................................................. 71
3.5.1. Saturation Vapor Pressure ....................... 71
3.5.2. Evaporation Rate ................................ 74
References ................................................. 77
4. Gas Flow .................................................... 79
4.1. Types of Flow, Definitions ............................. 79
4.1.1. Characterizing Flow, Knudsen Number, Reynolds
Number .......................................... 79
4.1.2. Gas Flow, Throughput, Pumping Speed ............. 83
4.1.3. Flow Resistance, Flow Conductance ............... 87
4.1.4. Effective Pumping Speed of a Vacuum Pump ........ 88
4.2. Inviscid Viscous Flow, Gas Dynamics .................... 90
4.2.1. Conservation Laws ............................... 90
4.2.2. Gradual Change of Cross-sectional Area:
Isentropic Change of State ...................... 91
4.2.3. Critical Flow ................................... 94
4.2.4. Choked Flow at Low Outlet Pressure .............. 96
4.2.5. Contraction of Flow into Aperture and Tube ...... 98
4.2.6. Examples of Nozzle Flow ......................... 98
4.2.7. Straight and Oblique Compression Shocks ........ 102
4.2.8. Laval Nozzle, Effluent Flow against
Counterpressure ................................ 105
4.2.9. Flow around a Corner (Prandtl-Meyer Flow) ...... 107
4.3. Frictional-Viscous Flow through a Tube ................ 110
4.3.1. Laminar and Turbulent Flow through a Tube ...... 110
4.3.2. Airflow through a Tube ......................... 114
4.3.3. Air Inflow to a Vessel, Examples ............... 117
4.3.4. Tube at the Inlet of a Pump, Examples .......... 121
4.3.5. Flow through Ducts with Non-circular Cross
Sections ....................................... 124
4.3.6. Influence of Gas Species on Flow ............... 126
4.4. Molecular Flow under High-vacuum and Ultrahigh-
vacuum Conditions ..................................... 127
4.4.1. Flow Pattern, Definitions, Transmission
Probability .................................... 127
4.4.2. Molecular Flow through an Aperture ............. 131
4.4.3. Molecular Flow through a Tube with Constant
Cross-sectional Area ........................... 133
4.4.4. Molecular Flow through a Tube with Circular
Cross Section .................................. 235
4.4.5. Molecular Flow through Tubes with Simple
Cross-sectional Geometry ....................... 136
4.4.6. Tube Bend and Tube Elbow ....................... 138
4.4.7. Series Connection of Tube and Aperture ......... 141
4.4.8. Series Connection of Components ................ 142
4.4.9. Molecular Flow through Conical Tube with
Circular Cross Section (Funnel) ................ 145
4.4.10.Component in the Inlet Line of a Pump .......... 146
4.5. Flow throughout the Entire Pressure Range ............. 147
4.5.1. Flow Ranges .................................... 147
4.5.2. Flow through a Thin Aperture with Circular
Cross Section .................................. 147
4.5.3. Flow through a Long Tube with Circular Cross
Section ........................................ 150
4.6. Flow with Temperature Difference, Thermal Effusion,
Transpiration ......................................... 154
4.7. Measuring Flow Conductances ........................... 158
4.7.1. Necessity of Measurement ....................... 158
4.7.2. Measurement of Intrinsic Conductances
(Inherent Conductances) ........................ 158
4.7.3. Calculation of Reduced Conductance (Assembly
Conductance) ................................... 160
4.1 Л. Measuring Reduced Conductances ................. 160
References ............................................ 162
Further Reading ....................................... 162
5. Analytical and Numerical Calculations of Rarefied Gas
Flows ...................................................... 163
5.1. Main Concepts ......................................... 163
5.1.1. Knudsen Number and Gas Rarefaction ............. 163
5.1.2. Macroscopic Quantities ......................... 164
5.1.3. Velocity Distribution Function ................. 164
5.1.4. Global Equilibrium ............................. 165
5.1.5. Local Equilibrium .............................. 166
5.1.6. Boltzmann Equation ............................. 166
5.1.7. Transport Coefficients ......................... 168
5.1.8. Model Equations ................................ 170
5.1.9. Gas-surface Interaction ........................ 171
5.2. Methods of Calculations of Gas Flows .................. 174
5.2.1. General Remarks ................................ 174
5.2.2. Deterministic Methods .......................... 174
5.2.3. Probabilistic Methods .......................... 176
5.3. Velocity Slip and Temperature Jump Phenomena .......... 178
5.3.1. Viscous Slip Coefficient ....................... 178
5.3.2. Thermal Slip Coefficient ....................... 180
5.3.3. Temperature Jump Coefficient ................... 181
5.4. Momentum and Heat Transfer Through Rarefied Gases ..... 182
5.4.1. Plane Couette Flow ............................. 182
5.4.2. Cylindrical Couette Flow ....................... 184
5.4.3. Heat Transfer Between Two Plates ............... 187
5.4.4. Heat Transfer Between Two Coaxial Cylinders .... 190
5.5. Flows Through Long Pipes .............................. 193
5.5.1. Definitions .................................... 194
5.5.2. Free-molecular Regime .......................... 195
5.5.3. Slip Flow Regime ............................... 196
5.5.4. Transitional Regime ............................ 197
5.5.5. Arbitrary Pressure and Temperature Drops ....... 202
5.5.6. Variable Cross Section ......................... 206
5.5.7. Thermo-molecular Pressure Ratio ................ 208
5.6. Flow Through an Orifice ............................... 211
5.7. Modeling of Holweck Pump .............................. 213
References ................................................. 218
6. Sorption and Diffusion ..................................... 221
6.1. Sorption Phenomena and the Consequences, Definitions
and Terminology ....................................... 221
6.2. Adsorption and Desorption Kinetics .................... 226
6.2.1. Adsorption Rate ................................ 226
6.2.2. Desorption Rate ................................ 227
6.2.3. Hobson Model of a Pump-down Curve .............. 228
6.2.4. Monolayer Adsorption Isotherms ................. 232
6.2.5. Multilayer Adsorption and Brunauer-Emmett-
Teller (BET) Isotherm .......................... 234
6.2.6. Monolayer Time ................................. 236
6.3. Absorption, Diffusion, and Outgassing ................. 237
6.4. Permeation ............................................ 243
References ................................................. 245
Further Reading ............................................ 245
7. Positive Displacement Pumps ................................ 247
7.1. Introduction and Overview ............................. 247
7.2. Oscillating Positive Displacement Pumps ............... 250
7.2.1. Piston Pumps ................................... 250
7.2.2. Diaphragm Pumps ................................ 252
7.2.2.1. Design and Principle of Operation ..... 252
7.2.2.2. Pumping Speed and Ultimate Pressure ... 253
7.2.2.3. Gas Ballast ........................... 255
7.2.2.4. Drive Concepts ........................ 256
7.2.2.5. Ultimate Pressure ..................... 256
7.2.2.6. Influence of Gas Species on Pumping
Speed and Ultimate Pressure ........... 257
7.2.2.7. Influence of Rotational Speed on
Ultimate Pressure ..................... 257
7.2.2.8. Design Principles ..................... 259
7.2.2.9. Diaphragm Pumps in Chemical
Laboratories .......................... 260
7.2.2.10.Diaphragm Pumps as Backing Pumps to
Turbomolecular Pumps .................. 260
7.2.2.11.Diaphragm Pumps Combined with other
Types of Vacuum Pumps ................. 264
7.3. Single-shaft Rotating Positive Displacement Pumps ..... 265
7.3.1. Liquid Ring Vacuum Pumps ....................... 265
7.3.1.1. Design and Principle of Operation ..... 265
7.3.1.2. Operating Properties and
Dimensioning .......................... 267
7.3.1.3. Designs ............................... 270
7.3.1.4. Pump Units with Liquid Ring Vacuum
Pumps ................................. 272
7.3.1.5. Suggestions for Economical
Operation ............................. 275
7.3.2. Sliding Vane Rotary Pumps ...................... 277
7.3.2.1. Operating Principle and Design ........ 277
7.3.2.2. Dry Running Sliding Vane Rotary
Pumps ................................. 278
7.3.2.3. Oil-lubricated Sliding Vane Rotary
Pumps ................................. 279
7.3.2.4. Once-through Lubricated Sliding
Vane Rotary Pumps ..................... 281
7.3.2.5. Operating Behavior and
Recommendations ....................... 282
7.3.2.6. Characteristic Curves and Ratings ..... 284
7.3.3. Rotary Plunger Pumps ........................... 286
7.3.3.1. Principle of Operation and
Technical Design ...................... 286
7.3.3.2. A Comparison of Sliding Vane
Rotary Pumps and Rotary Plunger
Pumps ................................. 289
7.3.4. Trochoidal Pumps ............................... 290
7.3.5. Scroll Pumps ................................... 291
7.3.5.1. Principle of Compression .............. 292
7.3.5.2. Design ................................ 293
7.3.5.3. Applications and Advantages ........... 294
7.4. Twin-spool Rotating Positive Displacement Pumps ....... 295
7.4.1. Screw Type Pumps ............................... 295
7.4.1.1. Operating Principle and Technical
Design ................................ 295
7.4.1.2. Heat Behavior and Technical Notes ..... 302
7.4.2. Claw Pumps ..................................... 303
7.4.2.1. Compression Principle ................. 304
7.4.2.2. Comparison with Roots Pumps ........... 307
7.4.2.3. Multistage Claw Pumps and Pump
Combinations .......................... 307
7.4.2.4. Speed Control ......................... 309
7.4.2.5. Fields of Application ................. 309
7.4.3. Roots Pumps .................................... 309
7.4.3.1. Principle of Operation ................ 310
7.4.3.2. Technical Setup ....................... 311
7.4.3.3. Theoretical Basics .................... 313
7.4.3.4. Effective Gas Flow .................... 313
7.4.3.5. Compression Ratio Ко at Zero
Delivery .............................. 313
7.4.3.6. Effective Compression Ratio and
Volumetric Efficiency ................ 315
7.4.3.7. Gradation of Pumping Speed between
Fore Pump and Roots Pump .............. 316
7.4.3.8. Pumping Speed and Ultimate Pressure ... 319
7.4.3.9. Installation and Operating
Suggestions ........................... 322
7.5. Specific Properties of Oil-sealed Positive
Displacement Pumps .................................... 323
7.5.1. Pumping Speed and Producible Ultimate
Pressure ....................................... 323
7.5.1.1. Pumping Speed and Ultimate Partial
Pressure .............................. 323
7.5.1.2. Ultimate Pressure and Oil Selection ... 325
7.5.2. Oil Backflow ................................... 328
7.6. Basics of Positive Displacement Pumps ................. 329
7.6.1. Pumping Down Vapors - Gas Ballast .............. 329
7.6.2. Power Requirements ............................. 333
7.6.2.1. Isothermal Compression ................ 334
7.6.2.2. Adiabatic Compression ................. 334
7.6.2.3. Polytropic Compression ................ 335
7.6.2.4. Compression Power ..................... 335
7.7. Operating and Safety Recommendations .................. 337
7.7.1. Installation ................................... 337
7.7.2. Starting and Shut Down, Inlet Valves ........... 338
7.7.3. Pump Selection and Operating Recommendations ... 339
7.7.4. Technical Safety Recommendations ............... 340
7.8. Specific Accessories for Positive Displacement
Pumps ................................................. 342
7.8.1. Sorption Traps ................................. 342
7.8.2. Safety Valves .................................. 343
7.8.3. Oil Filter and Oil Cleaning .................... 343
7.8.4. Exhaust Filter (Oil-mist Separator) ............ 345
7.8.5. Dust Filters ................................... 346
References ................................................ 348
Further Reading on Positive Displacement Pumps ............ 351
8. Condensers ................................................. 353
8.1. Condensation Processes under Vacuum ................... 353
8.1.1. Fundamentals ................................... 353
8.1.2. Condensation of Pure Vapors .................... 355
8.1.3. Condensation of Gas-Vapor Mixtures ............. 359
8.1.4. Coolants ....................................... 362
8.2. Condenser Designs ..................................... 362
8.2.1. Surface Condensers for Liquid Condensation ..... 362
8.2.2. Direct Contact Condensers ...................... 364
8.2.3. Condensate Discharge ........................... 366
8.2.4. Surface Condensers for Solid Condensation ...... 368
8.3. Integrating Condensers into Vacuum Systems ............ 368
8.3.1. Condensers Combined with Vacuum Pumps .......... 368
8.3.2. Control ........................................ 372
8.4. Calculation Examples .................................. 372
References ............................................ 374
9. Jet and Diffusion Pumps .................................... 375
9.1. Introduction, Overview ................................ 375
9.2. Liquid Jet Vacuum Pumps ............................... 377
9.3. Steam Jet Vacuum Pumps ................................ 379
9.3.1. Design and Function ............................ 379
9.3.2. Performance Data, Operating Behavior, and
Control ........................................ 381
9.3.3. Multistage Steam Jet Vacuum Pumps .............. 384
9.3.4. Organic Vapors as Driving Pump Fluids .......... 387
9.4. Diffusion Pumps ....................................... 388
9.4.1. Design and Principle of Operation .............. 388
9.4.2. Pump Fluids .................................... 393
9.4.3. Baffles and Vapor Traps ........................ 394
9.4.4. Fractionating and Degassing .................... 395
9.4.5. Operating Suggestions .......................... 397
9.4.6. Pumping Speed, Critical Backing Pressure,
Hybrid Pumps ................................... 397
9.4.7. Calculating Performance Characteristics of
Diffusion and Vapor Jet Pumps by Using a
Simple Pump Model .............................. 400
9.5. Diffusion Pumps versus Vapor Jet Pumps ................ 408
References ............................................ 410
Further Reading on Positive Displacement Pumps ........ 411
10.Molecular and Turbomolecular Pumps ......................... 413
10.1.Introduction .......................................... 413
10.2.Molecular Pumps ....................................... 415
10.2.1.Gaede Pump Stage ............................... 416
10.2.2.Holweck Pump Stage ............................. 419
10.2.3.Siegbahn Pump Stage ............................ 420
10.3.Physical Fundamentals of Turbomolecular Pump Stages ... 421
10.3.1.Pumping Mechanism ............................. 421
10.3.2.Pumping Speed and Compression Ratio ............ 422
10.3.3.Gaede and Statistical Theory of the Pumping
Effect ......................................... 423
10.3.4.Thermal Balance ................................ 426
10.4.Turbomolecular Pumps .................................. 430
10.4.1.Design ......................................... 430
10.4.2.Operating Principle ............................ 430
10.4.3.Rotor Materials and Mechanical Requirements .... 431
10.4.4.Heating and Cooling ............................ 433
10.4.5.Special Designs ................................ 433
10.4.6.Safety Requirements ............................ 435
10.4.7.Bearing Arrangements for Rotors in
Turbomolecular Pumps ........................... 436
10.4.7.1.Shaft with Two Ball Bearings .......... 436
10.4.7.2.Shaft with Permanent Magnet Bearing
and Ball Bearing ...................... 437
10.4.7.3.Magnetic Bearings ..................... 437
10.4.8.Drives and Handling ............................ 439
10.4.9.Performance Characteristics .................... 440
10.4.9.1.Pumping Speed ......................... 440
10.4.9.2.Compression Ratio, Ultimate
Pressure, Base Pressure ............... 441
10.4.9.3.Pump-down Times for Vacuum Chambers ... 442
10.4.9.4.Pumping of High Gas Throughputs ....... 444
10.4.10.Operation and Maintenance ..................... 445
10.4.10.1.Backing Pump Selection ............... 445
10.4.10.2.General Notes ........................ 446
10.4.10.3.Start-up ............................. 446
10.4.10.4.Obtaining Base Pressure .............. 446
10.4.10.5.Operation in Magnetic Fields ......... 446
10.4.10.6.Venting .............................. 446
10.4.10.7.Maintenance .......................... 447
10.4.11.Applications .................................. 448
References ................................................. 450
11.Sorption Pumps ............................................. 453
11.1.Introduction ......................................... 453
11.2.Adsorption Pumps ...................................... 455
11.2.1.Working Principle .............................. 455
11.2.2.Design ......................................... 457
11.2.3.Ultimate Vacuum and Pumping Speed .............. 458
11.2.3.1.Ultimate Pressure with a Single
Adsorption Pump ....................... 458
11.2.3.2.Ultimate Pressure with two or more
Adsorption Pumps ...................... 459
11.2.4.Improving Ultimate Vacuum by Pre-evacuation
or Filling with Foreign Gas .................... 461
11.2.5.Operating Suggestions .......................... 461
11.3.Getter ................................................ 463
11.3.1.Mode of Operation and Getter Types ............. 463
11.3.2.NEG Pumps ...................................... 464
11.3.2.1.Fundamentals of Bulk Getters/NEG ...... 464
11.3.2.2.Design of NEG Pumps ................... 468
11.3.2.3.Pumping Speed and Getter Capacity ..... 469
11.3.2.4.Applications of NEG Pumps ............. 471
11.3.2.5.Safety and Operating
Recommendations ....................... 472
11.3.3.Evaporation/sublimation Pumps .................. 473
11.3.3.1.Evaporation Materials ................. 473
11.3.3.2.Pumping Speed ......................... 474
11.3.3.3.Getter Capacity ....................... 477
11.3.3.4.Design of Evaporation Getters ......... 478
11.4.Ion Getter Pumps ...................................... 482
11.4.1.Working Principle .............................. 482
11.4.2.Technical Design (Diode Type) .................. 487
11.4.3.Pumping Speed .................................. 487
11.4.4.The Differential Ion Pump ...................... 490
11.4.5.Triode Pumps ................................... 491
11.4.6.Distributed Ion Pumps .......................... 494
11.4.7.Residual Gas Spectrum .......................... 494
11.4.8.Operation ...................................... 495
11.5.Orbitron Pumps ........................................ 496
References ................................................. 498
Further Reading ............................................ 499
12.Cryotechnology and Cryopumps ............................... 501
12.1.Introduction .......................................... 501
12.2.Methods of Refrigeration .............................. 502
12.2.1.Concepts and Fundamental Laws of
Thermodynamics ................................. 502
12.2.2.Special Cooling Processes ...................... 505
12.2.2.1.Joule-Thomson Expansion, Linde
Process ............................... 505
12.2.2.2.Expansion Engines ..................... 507
12.2.2.3.Claude Process ........................ 508
12.2.2.4.Stirling Process ...................... 509
12.2.2.5.Gifford-McMahon Process ............... 510
12.2.2.6.General Characteristics of
Refrigerating Systems ................. 511
12.2.2.7.Low-temperature Measurement ........... 513
12.3.Cryostat Technology ................................... 513
12.3.1.Cryostats ...................................... 513
12.3.2.Vacuum-insulated Ducts ......................... 517
12.3.3.Refilling Equipment ............................ 518
12.3.4.Cooling Agent Loss ............................. 523
12.4.Cryopumps ............................................. 527
12.4.1.Binding of Gases to Cold Surfaces .............. 529
12.4.1.1.Gas Condensation ...................... 529
12.4.1.2.Cryotrapping and Cryosorption ......... 529
12.4.2.Characteristics of Cryopumps ................... 533
12.4.2.1.Starting Pressure PSt ................. 533
12.4.2.2.Ultimate Pressure Pult ................ 533
12.4.2.3.Pumping Speed ......................... 535
12.4.2.4.Service Life tS ...................... 536
12.4.2.5.Capacity (Maximum Gas Intake) ......... 537
12.4.2.6.Heat Transfer to the Cold Surface ..... 538
12.4.2.7.Thermal Conductivity of Condensate .... 539
12.4.2.8.Growth Rate of the Condensate Layer ... 540
12.4.2.9.Crossover Value ....................... 540
12.4.2.10.Maximum Tolerable pV Flow ............ 541
12.4.3.Designs ........................................ 541
12.4.3.1.Bath Cryopumps ........................ 542
12.4.3.2.Evaporator Cryopumps .................. 543
12.4.3.3.Cryopumps with Refrigerating
Machines (Refrigerator Cryopumps) ..... 544
12.4.3.4.Examples of Applications .............. 548
12.4.3.5.Cryopumps in Nuclear Fusion
Technology ............................ 548
12.4.3.6.Cryopumps in Aerospace Technology ..... 548
12.4.3.7.Cryopumps in Particle Accelerators .... 550
12.4.3.8.Cryopumps in Industrial Systems ....... 550
12.4.3.9.Cryopumps for UHV Systems ............. 551
12.4.4.Development Trends for Cryopumps ............... 552
References ............................................ 553
13.Total Pressure Vacuum Gauges ............................... 555
13.1.Introduction .......................................... 555
13.2.Mechanical Vacuum Gauges .............................. 556
13.2.1.Principle and Classification ................... 556
13.2.2.Corrugated-diaphragm Vacuum Gauges ............. 557
13.2.3.Capsule Element Vacuum Gauges (Measuring
Range lkPa-lOOkPa) ............................. 558
13.2.4.Bourdon Tube Vacuum Gauges (Measuring Range
lkPa-lOOkPa) ................................... 559
13.2.4.1.Quartz Bourdon Tube Vacuum Gauges ..... 560
13.2.5.Diaphragm (Membrane) Vacuum Gauges ............. 561
13.2.5.1.Diaphragm (Membrane) Vacuum Gauges
with Mechanical Displays (Measuring
Range 0.1 kPa-100 kPa) ................ 561
13.2.5.2.Diaphragm (Membrane) Vacuum Gauges
with Electrical Converters ............ 563
13.2.5.3.Diaphragm (Membrane) Vacuum Gauges
Using the Piezoresistive Principle .... 564
13.2.5.4.Piezoelectric Vacuum Gauges ........... 565
13.2.5.5.Resonant Diaphragm Vacuum Gauges ...... 565
13.2.5.6.Capacitance Diaphragm Vacuum Gauges ... 566
13.2.5.7.Thermal Transpiration ................. 569
13.2.6.Pressure Switches and Pressure Controllers ..... 571
13.3.Spinning Rotor Gauges (Gas-friction Vacuum Gauges) .... 573
13.3.1.Measuring Setup and Measuring Principle ........ 574
13.3.2.Retarding Effect due to Gas Friction ........... 575
13.3.3.Measuring Procedure ............................ 579
13.3.4.Extending the Measuring Range towards Higher
Pressures ...................................... 580
13.3.5.Measuring Uncertainty .......................... 582
13.4.Direct Electric Pressure Measuring Transducers ........ 583
13.5.Thermal Conductivity Vacuum Gauges ............... 583
13.5.1.Principle ...................................... 583
13.5.2.Thermal Conductivity Vacuum Gauges with
Constant Wire Temperature ...................... 587
13.5.3.Thermal Conductivity Vacuum Gauges with
Constant Heating ............................... 590
13.5.4.Thermocouple Vacuum Gauges ..................... 592
13.5.5.Thermistors .................................... 593
13.5.6.Guidelines for Operating Thermal Conductivity
Vacuum Gauges .................................. 593
13.6.Thermal Mass Flowmeters ............................... 594
13.7.Ionization Gauges ..................................... 596
13.7.1.Principle and Classification ................... 596
13.7.2.History of Ionization Gauges ................... 597
13.7.3.Emitting-cathode Ionization Gauges (Hot-
cathode Ionization Gauges) ..................... 599
13.7.3.1.Measurement Principle ................. 599
13.7.3.2.Design of Emitting-cathode
Ionization Gauges (Hot-cathode
Ionization Gauges) .................... 603
13.7.3.3.Concentric Triode ..................... 604
13.7.3.4.Fine-vacuum Ionization Gauges ......... 604
13.7.3.5.Bayard-Alpert Ionization Gauges ....... 605
13.7.3.6.Extractor Ionization Gauges ........... 610
13.7.3.7.Additional Types of Emitting-cathode
Ionization Gauges ..................... 613
13.7.3.8.Operating Suggestions for Emitting-
cathode Ionization Gauges ............. 614
13.7.4.Crossed-field Ionization Gauges ................ 615
13.7.4.1.Penning Gauges ........................ 615
13.7.4.2.Magnetron and Inverted Magnetron ...... 620
13.7.5.Comparison of Both Types of Ionization
Gauges ......................................... 622
13.7.6.General Suggestions ............................ 623
References ................................................. 627
14.Partial Pressure Vacuum Gauges and Leak Detectors .......... 631
14.1.Introduction .......................................... 631
14.2.Partial Pressure Analysis by Mass Spectrometry ........ 631
14.2.1.Ion Source Design .............................. 637
14.2.1.1.Open Ion Sources (OIS) ................ 638
14.2.1.2.Closed Ion Sources (CIS) .............. 639
14.2.1.3.Molecular Beam Ion Sources (MBIS) ..... 640
14.2.2.Filament Materials ............................. 641
14.2.3.Artifacts in the Mass Spectrum due to the
Ion Source ..................................... 642
14.2.4.Mass Analyzers ................................. 643
14.2.4.1.Quadrupole Mass Analyzers ............. 644
14.2.4.2.Miniaturized Quadrupole Mass
Analyzers ............................. 648
14.2.4.3.Magnetic Sector Analyzers ............. 649
14.2.5.Ion Detectors .................................. 653
14.2.5.1.Faraday Cups .......................... 653
14.2.5.2.Secondary Electron Multiplier
Detection ............................. 654
14.2.5.3.Discrete Dynode Electron
Multipliers ........................... 655
14.2.5.4.Continuous Dynode Electron
Multipliers (CDEM) .................... 656
14.2.5.5.MicroChannel Plate Detectors .......... 657
14.2.6.Software for Mass Spectrometer Control ......... 658
14.2.6.1.Analog Scan, Ion Current versus
Mass .................................. 658
14.2.6.2.Selected Peaks, Ion Current versus
Time .................................. 659
14.2.6.3.Leak Detection Mode ................... 659
14.2.7.Further Applications of Mass Spectrometers ..... 659
14.3.Partial Pressure Measurement using Optical Methods .... 659
14.4.Leak Detectors ........................................ 662
14.4.1.Basic Principles and Historical Overview ....... 662
14.4.2.Helium Leak Detectors .......................... 663
14.4.2.1.Requirements and General Functions
of Vacuum Leak Detection .............. 663
14.4.2.2.Helium Sector Field Mass
Spectrometers ......................... 664
14.4.2.3.Inlet Pressure of Helium Leak
Detectors ............................. 665
14.4.2.4.Time Response of Helium Leak
Detectors ............................. 666
14.4.2.5.Operating Principles of Helium Leak
Detectors ............................. 667
14.4.2.6.Sniffing Devices for Helium Leak
Detectors ............................. 671
14.4.2.7.Applications of Mass Spectrometer
Helium Leak Detectors ................. 672
14.4.3.Refrigerant Leak Detectors ..................... 672
14.4.3.1.Design and Operating Principle ........ 672
14.4.3.2.Applications .......................... 675
14.4.4.Reference Leaks ................................ 675
14.4.4.1.Permeation Leaks ...................... 675
14.4.4.2.Conductance Leaks ..................... 676
14.4.4.3.Practical Realization of Reference
Leaks ................................. 676
14.4.4.4.Calibrating Reference Leaks ........... 677
14.4.5.Measuring Characteristics and Calibration
of Leak Detectors .............................. 677
14.4.5.1.Leak Detectors as Test Equipment
According to ISO 9001 ................. 677
14.4.5.2.Calibration Uncertainty ............... 678
14.4.6.Leak Detectors Based on Other Sensor
Principles ..................................... 679
14.4.6.1.Helium Sniffers with Quartz Glass
Membrane .............................. 679
14.4.6.2.Halogen Leak Detectors with Alkali
Ion Sensors ........................... 679
14.4.6.3.Halogen Leak Detectors with
Infrared Sensors ...................... 680
References ................................................. 680
15.Calibrations and Standards ................................. 685
15.1.Introduction .......................................... 685
15.2.Calibration of Vacuum Gauges .......................... 688
15.2.1.Primary Standards .............................. 688
15.2.1.1.Liquid Manometers ..................... 689
15.2.1.2.Compression Manometer after McLeod .... 692
15.2.1.3.Piston Gauges and Pressure Balances ... 695
15.2.1.4.Static Expansion Method ............... 698
15.2.1.5.Continuous Expansion Method ........... 703
15.2.1.6.Other Primary Standards ............... 709
15.2.2.Calibration by Comparison ...................... 710
15.2.3.Capacitance Diaphragm Gauges ................... 711
15.2.4.Spinning Rotor Gauges .......................... 716
15.2.5.Ionization Gauges .............................. 718
15.3.Calibrations of Residual Gas Analyzers ................ 720
15.4.Calibration of Test Leaks ............................. 723
15.5.Standards for Determining Characteristics of
Vacuum Pumps .......................................... 726
References ................................................. 729
16.Materials .................................................. 733
16.1.Requirements and Overview of Materials ................ 733
16.2.Materials for Vacuum Technology ....................... 734
16.2.1.Metals ......................................... 734
16.2.1.1.The most Important Metals and Metal
Alloys ................................ 735
16.2.2.Technical Glass ................................ 739
16.2.2.1.Basics ................................ 739
16.2.2.2.Properties of Important Glasses ....... 741
16.2.3.Ceramic Materials .............................. 743
16.2.3.1.Basics ................................ 743
16.2.3.2.Properties of Important Ceramics ...... 743
16.2.3.3.Ceramics in Vacuum Technology ......... 744
16.2.3.4.Ceramic/Metal Joining Technologies .... 744
16.2.3.5.Zeolite ............................... 747
16.2.4.Plastics ....................................... 747
16.2.4.1.Basics ................................ 747
16.2.4.2.Properties of Major Plastics .......... 747
16.2.5.Vacuum Greases ................................. 749
16.2.6.Oils ........................................... 750
16.2.7.Coolants ....................................... 750
16.3.Gas Permeability and Gas Emissions of Materials ....... 751
16.3.1.Fundamentals ................................... 751
16.3.2.Gas Permeability ............................... 751
16.3.2.1.Gas Permeability of Metals ............ 751
16.3.2.2.Gas Permeability of Glasses and
Ceramics .............................. 753
16.3.2.3.Gas Permeability of Plastics .......... 754
16.3.3.Gas Emissions .................................. 756
16.3.3.1.Basics ................................ 756
16.3.3.2.Saturation Vapor Pressure (see also
Section 3.5.1) ........................ 756
16.3.3.3.Surface Desorption, Gas Diffusion
from Bulk Material, Reference
Values for Gas Emissions .............. 758
16.3.3.4.Gas Diffusion from Bulk Material ...... 758
16.3.3.5.Reference Values for Total Gas
Emission Rates ........................ 762
References ................................................. 762
Further Reading ............................................ 763
17.Vacuum Components and Seals ................................ 765
17.1.I ntroduction ......................................... 765
17.2.Permanent Connections ................................. 765
17.2.1.Welded Joints .................................. 766
17.2.1.1.TIG (Tungsten Inert-gas) Welding ...... 766
17.2.1.2.Micro-plasma Welding, Electron-
beam Welding, Friction Welding ........ 767
17.2.2.Brazed Joints .................................. 767
17.2.3.Fused Joints ................................... 768
17.2.4.Joints with Metallizations ..................... 771
17.2.5.Cemented Joints ................................ 772
17.3.Detachable Joints ..................................... 772
17.3.1.Seals and Sealing Faces ........................ 772
17.3.2.Required Forces ................................ 773
17.3.3.Ground-in Connections .......................... 774
17.3.4.Flange Connections ............................. 775
17.3.4.1.Swagelok® and Swagelok®-VCR®
connectors ............................ 775
17.3.4.2.Klein Flange Components and Seals
According to DIN 28403 (ISO 2861-1) ... 776
17.3.4.3.ISO-K Components and Seals
According to DIN 28404 (ISO 1609) ..... 777
17.3.4.4.CF Components and Seals (ISO/TS
3669-2) ............................... 777
17.3.4.5.COF Components ........................ 778
17.3.4.6.Special Flanges and Special Seals ..... 779
17.3.4.7.Vacuum Components and Vessels ......... 779
17.3.4.8.Plug-type Connectors .................. 780
17.4.Vacuum Vessels ........................................ 781
17.4.1.Design ......................................... 781
17.4.1.1.Dimensioning of Vacuum Vessels and
Calculation Examples .................. 782
17.4.2.Double-walled Vessels .......................... 784
17.5.Flexible Joints ....................................... 785
17.6.Feedthroughs .......................................... 787
17.6.1.Feedthroughs for Motion and Mechanical
Energy ......................................... 787
17.6.1.1.Feedthroughs for Linear Motion ........ 787
17.6.1.2.Feedthroughs for Rotary Motion ........ 788
17.6.1.3.Manipulators .......................... 788
17.6.2.Electrical Feedthroughs ........................ 789
17.6.2.1.Plastic Feedthroughs .................. 789
17.6.2.2.Ceramic Feedthroughs .................. 790
17.6.3.Feedthroughs for Liquids and Gases ............. 792
17.6.3.1.Windows ...................................... 793
17.6.4.Lubrication under Vacuum ....................... 793
17.7.Valves ................................................ 795
17.7.1.Basics ......................................... 795
17.7.1.1.Design, Dimensioning, and
Requirements .......................... 796
17.7.1.2.Classification (Terms) ................ 796
17.7.1.3.Actuation ............................. 796
17.7.1.4.Sealing of Valves and Materials ....... 797
17.7.2.Corner Valves .................................. 797
17.7.3.Straight-way Valves ............................ 798
17.7.4.Sliding Valves ................................. 800
17.7.5.Gas Dosing Valves .............................. 801
17.8.Manufacturing and Surface Treatment of Vacuum
Components ............................................ 802
17.8.1.Machining Techniques ........................... 802
17.8.2.Surface Treatment .............................. 803
17.8.3.Cleaning (Pre-cleaning and In-Situ) ............ 805
17.8.3.1.Cleaning of Stainless Steel ........... 806
17.8.3.2.Cleaning of Technical Glass ........... 806
17.8.3.3.Cleaning of Ceramics .................. 807
17.8.3.4.Vacuum Annealing ...................... 807
17.8.3.5.Baking ................................ 807
17.8.3.6.In-Situ Cleaning by Means of Glow
Discharge and Chemically Active Gas ... 808
References ................................................. 809
18.Operating Vacuum Systems ................................... 811
18.1.Electronic Integration of Vacuum Systems .............. 811
18.1.1.Control by Means of Process Sensors and
Automated Data Processing ...................... 811
18.1.1.1.Requirements and Applications ......... 811
18.1.2.Integrated Solutions ........................... 812
18.1.2.1.Integration using Windows Winsock ............ 814
18.1.2.2.ASCII Protocols ....................... 814
18.1.2.3.Standardized Bus Systems .............. 815
18.1.2.4.Sensor Integration According to SECS
and HSMS Standards .................... 816
18.1.3.Process-data Analysis .......................... 818
18.2.General Guidelines for Ultimate and Working
Pressures ............................................. 820
18.2.1.Ultimate Pressure pult and Ultimate Working
Pressure pw.ult of a Vacuum Pump ............... 820
18.2.2.Ultimate Pressure pult s of a Vacuum
Apparatus or System ............................ 820
18.2.3.Working Pressure ............................... 821
18.2.4.Working Pressure Determined by Process Gas
Flow ........................................... 822
18.2.5.Working Pressure Determined by Evaporating
Substances ..................................... 823
18.2.6.Working Pressure Determined by Outgassing
(compare Chapter 6 and Section 16.3) ........... 826
18.2.7.Working Pressure Determined by Permeation
Gas Flow (compare Section 16.3.2) .............. 826
18.2.8.Working Pressure Determined by Leakage Gas
Flow ........................................... 827
18.3.Techniques for Operating Low-vacuum Systems
(101 kPa-100 Pa) ...................................... 827
18.3.1.Overview ....................................... 827
18.3.2.Assembly of Low-vacuum Systems ................. 829
18.3.3.Pumps: Types and Pumping Speeds ................ 829
18.3.4.Low-vacuum Pump Stands ......................... 830
18.3.5.Low-vacuum Pressure Measurement ................ 831
18.3.6.Pump-down Times in Low Vacuum .................. 831
18.3.7.Venting ........................................ 837
18.4.Techniques for Operating Fine-vacuum Systems
(100 Pa-0.1 Pa, 1 mbar-l0-3 mbar) ..................... 839
18.4.1.Overview ....................................... 839
18.4.2.Assembly of Fine-vacuum Systems ................ 839
18.4.3.Pumps: Types and Pumping Speeds ................ 840
18.4.4.Pressure Measurement ........................... 840
18.4.5.Pump-down Time and Ultimate Pressure ........... 841
18.4.6.Venting ........................................ 845
18.4.7.Fine-vacuum Pump Stands ........................ 845
18.5.Techniques for Operating High-vacuum Systems
(10-1 Pa-10-5 Pa, 10-3 mbar-l0-7 mbar) .................. 847
18.5.1.Pumps: Types and Pumping Speeds ................ 849
18.5.2.Treatment of Vacuum Gauges (Cleaning) .......... 850
18.5.3.High-vacuum Pump Stands ........................ 851
18.5.3.1.High-vacuum Pump Stands with
Diffusion Pumps (see also Section
9.4.6) ................................ 851
18.5.3.2.High-vacuum Pump Stands with
Turbomolecular Pumps .................. 859
18.5.3.3.Fully Automatic High-vacuum Pump
Stands ................................ 860
18.5.4.Pump-down Time and Venting .............. 861
18.6.Techniques for Operating Ultrahigh-vacuum Systems
(p < 10-5 Pa, 10-7 mbar) ............................ 862
18.6.1.Overview ....................................... 862
18.6.2.Design of UHV Systems .......................... 863
18.6.3.Operating Guidelines for UHV Pumps ............. 864
18.6.3.1.Adsorption Pumps ...................... 864
18.6.3.2.Ion Getter Pumps ...................... 865
18.6.3.3.Titanium Evaporation Pumps ............ 866
18.6.3.4.Turbomolecular Pumps .................. 867
18.6.3.5.Cryopumps ............................. 867
18.6.3.6.Bulk Getter (NEG) Pumps ............... 867
18.6.4.Pressure Measurement ........................... 868
18.6.5.Pump-down Times, Ultimate Pressure, and
Evacuating Procedures .......................... 868
18.6.6.Venting ........................................ 869
18.6.7.Ultrahigh-vacuum Systems ....................... 869
18.6.8.Ultrahigh-vacuum (UHV) Components .............. 869
18.6.9.Ultrahigh-vacuum (UHV) Pump Stands ............. 870
18.6.9.1.Large Ultrahigh-vacuum (UHV)
Facilities ............................ 873
References ............................................ 875
19.Methods of Leak Detection .................................. 877
19.1.Overview .............................................. 877
19.1.1.Vacuum Leak Detection .......................... 877
19.1.2.Overpressure Leak Detection .................... 878
19.1.3.Search Gas Distribution in the Atmosphere
in front of a Leak ............................. 879
19.1.4.Measurement Results with the Sniffing Method ... 880
19.1.5.Search Gas Species ............................. 881
19.1.5.1.Helium ................................ 881
19.1.5.2.Noble Gases other than Helium ......... 881
19.1.5.3.Hydrogen H2 ........................... 882
19.1.5.4.Methane CH4 ........................... 882
19.1.5.5.Carbon Dioxide C02 .................... 882
19.1.5.6.Sulfur Hexafluoride SF6 ............... 882
19.2.Properties of Leaks ................................... 883
19.2.1.Leak Rate, Units ............................... 883
19.2.2.Types of Leaks ................................. 883
19.2.2.1.Properties of Pore-like Leaks ......... 885
19.2.2.2.Permeation Leaks ...................... 887
19.2.2.3.Virtual Leaks in Vacuum Vessels ....... 888
19.2.2.4.Liquid Leaks .......................... 888
19.3.Overview of Leak Detection Methods (see also DIN
EN 1779) .............................................. 889
19.3.1.General Guidelines for Tightness Testing ....... 889
19.3.2.Methods without Search Gas (Pressure
Testing) ....................................... 890
19.3.2.1.Introduction .......................... 890
19.3.2.2.Pressure Loss Measurement ............. 891
19.3.2.3.Pressure Rise Measurement ............. 892
19.3.2.4.Additional Methods .................... 893
19.3.3.Search Gas Methods without Helium .............. 894
19.3.3.1.Basics ................................ 894
19.3.3.2.Vacuum Leak Detection with Non-
helium Search Gas ..................... 894
19.3.3.3.Overpressure Leak Detection with
Search Gases other than Helium ........ 896
19.4.Leak Detection using Helium Leak Detectors ............ 896
19.4.1.Properties of Helium Leak Detectors ............ 896
19.4.2.Testing of Components .......................... 897
19.4.2.1.Testing Procedure, Integral Testing ... 897
19.4.2.2.Procedure for Leak Localization ....... 899
19.4.3.Testing of Vacuum Systems ...................... 901
19.4.3.1.General Considerations for Partial
Flow Operation ........................ 901
19.4.3.2.Points on Systems for Connecting
Leak Detectors ........................ 902
19.4.3.3.Detection Limit and Response Time ..... 905
19.4.4.Overpressure (Sniffing) Leak Detection with
a Helium Leak Detector ......................... 906
19.4.4.1.Integral Procedure (Total or
Partial) .............................. 907
19.4.4.2.Leak Localization with a Sniffer ...... 908
19.5.Leak Detection with Other Search Gases ................ 908
19.5.1.Basics ......................................... 908
19.5.2.Sniffing Leak Detection on Refrigerators and
Air Conditioners ............................... 908
19.6.Industrial Tightness Testing of Mass-production
Components ............................................ 909
19.6.1.Basics ......................................... 909
19.6.2.Industrial Testing of Series Components ........ 909
19.6.2.1.Envelope Testing Method for Vacuum
Components (Method Al in EN 1779) ..... 910
19.6.2.2.Vacuum Chamber Method for
Overpressure Components (Method B6
in EN 1779) ........................... 910
19.6.2.3.Testing of Hermetically Sealed
Components by Means of Bombing
(Method B5 in EN 1779) ................ 912
19.6.2.4.Testing of Food Packaging in
flexible Test Chambers ................ 913
References ................................................. 914
20.Appendix ................................................... 915
20.A.Tables ................................................ 915
20.В.Diagrams .............................................. 950
20.C.Common Abbreviations .................................. 965
20.D.Quantities and Units .................................. 966
20.E.Glossary, Symbols of Physical Quantities and their
SI Units used in this Book ............................ 968
Index ......................................................... 977
Directory of Products and Suppliers ........................... 997
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